Slopes
A researcher is investigating the relationship between the number of hours a student studies and their exam score. They collect data from a sample of students and perform a linear regression analysis. The resulting regression equation is , where is the predicted exam score and is the nu...
For every 1-hour increase in studying, the predicted exam score increases by 5 points.
For every 1-point increase in exam score, the predicted number of hours studied increases by 5 hours.
For every 1-hour increase in studying, the actual exam score increases by 5 points.
For every 1-point increase in exam score, the actual number of hours studied increases by 1 hour.
Which of the following scenarios best illustrates the identification of explanatory and response variables?
Analyzing the relationship between ice cream sales and crime rates, where ice cream sales are believed to influence crime rates.
Analyzing the relationship between hours of sunlight and plant growth, where plant growth is believed to depend on hours of sunlight.
Analyzing the relationship between the number of traffic lights in a city and the number of car accidents, with no assumed direction of influence.
Analyzing the relationship between the number of books a person owns and their level of happiness, assuming both are independent.
A scatterplot shows the relationship between the number of rainy days in a month and the number of umbrellas sold. The data points are clustered closely around a line that slopes upwards. Which of the following best describes the relationship?
There is a strong positive linear relationship between the number of rainy days and the number of umbrellas sold.
There is a weak positive linear relationship between the number of rainy days and the number of umbrellas sold.
There is a strong negative linear relationship between the number of rainy days and the number of umbrellas sold.
There is no linear relationship between the number of rainy days and the number of umbrellas sold.
A residual plot shows a distinct curved pattern. What condition for inference about the slope of the regression line is most likely violated?
Linearity
Independence
Normality
Equal Variance
A researcher is checking conditions for inference for linear regression. They observe that the residuals are clustered around the regression line for small values of x, but spread out more for larger values of x. Which condition is likely violated?
Linearity
Independence
Normality
Equal Variance
A study is conducted to investigate the relationship between hours of exercise per week and resting heart rate. The researchers collect data from a sample of individuals, but realize that all participants are members of the same gym. Which condition for inference is most likely violated?
Linearity
Independence
Normality
Equal Variance
A 95% confidence interval for the slope of a regression line is (2.5, 4.0). Which of the following is the correct interpretation of this interval?
We are 95% confident that the true slope of the population regression line is between 2.5 and 4.0.
We are 95% confident that the predicted slope of the sample regression line is between 2.5 and 4.0.
There is a 95% probability that the true slope of the population regression line is between 2.5 and 4.0.
95% of the data points fall within the interval (2.5, 4.0).

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Given the following summary statistics for a linear regression: sample size , slope , standard error of the slope , and critical t-value . Calculate the 95% confidence interval for the slope.
(0.674, 2.326)
(0.6, 2.4)
(0.67, 2.33)
(0.5, 2.5)
A researcher is testing the hypothesis that there is no linear relationship between two variables. Which of the following is the correct null and alternative hypothesis for a t-test for the slope?
,
,
,
,
Given a t-statistic of 2.5 and a standard error of the slope of 0.5, calculate the estimated slope.
0.5
1.25
2
5